Massive studies concern the development of low-carbon water and energysystems. Specifically, surfaces with special wettability to promote vapor-toliquidcondensation have been widely studied, but current solutions sufferfrom poor heat transfer performances due to inefficient droplet removal. Inthis study, the limit of condensation on a beetle-inspired biphilic quasi-liquidsurface (QLS) in a steam environment is pushed, which provides a heat flux100 times higher than that in atmospheric condensation. Unlike the beetleinspiredsurfaces that have sticky hydrophilic domains, the biphilic QLSconsists of PEGylated and siloxane polymers as hydrophilic and hydrophobicquasi-liquid patterns with the contact angle hysteresis of 3° and 1°, respectively.More importantly, each hydrophilic slippery pattern behaves like aslippery bridge that accelerates droplet coalescence and removal. As a result,the condensed droplets grow rapidly and shed off. It is demonstrated thatthe biphilic-striped QLS shows a 60 higher water harvesting rate in atmosphericcondensation and a 170 higher heat transfer coefficient in steam condensationthan the conventional beetle-inspired surface. This study providesa new paradigm to push the limit of condensation heat transfer at a high heatflux, which sheds light on the next-generation surface design for water andenergy sustainability.
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